Finger-Squeezing Device to Improve Capillary Refill Time Tests

Doctors measure “capillary refill time” by putting pressure on the fingernails and then watching the skin below go from white to red. It’s a way to assess hydration in patients, as well as to look for poor peripheral perfusion arising from other underlying conditions. Children, as well as others that can’t express themselves, can be easily tested for dehydration by such a method, but it remains subjective in the clinician’s eye, and each patient’s skin tone and normal refill times are different.

Bodkin Design and Engineering out of Newton, MA has developed a prototype system, originally conceived by Dr. Vassillios Bezzerides at Boston Children’s Hospital, that aims to make these tests more standardized, and therefore more clinically useful. The system includes a squeezer to pinch a finger and optical sensors that assess how the skin tone changes.